Alexander Booth, a 20-year-old chef from Huddersfield, was jailed earlier this month after being accused of throwing an object - believed to be a plastic cup - at police as ugly scenes played out in the city in south France.
Five other England supporters were also jailed for their part in violence which involved 150 “hyper violent” Russian fans ahead of the Euro 2016 game between Roy Hodgson’s side and Russia.
Nigel Booth, 53, from Brighouse, Calderdale, is in Nice for the Three Lions’ last 16 match against Iceland and had an England flag with #freeboothy written on for the game.
Speaking on the beach off the Promenade des Anglais, Mr Booth said: “If he had done it I would understand, but he didn’t. We think it’s political.
“He’s not a hooligan. He’s done nothing but mouth it off a little bit. It was his first tournament, he’d been saving up and planning this trip with my brother for 12 months.
“They had been in Marseille the day before (the violence) and enjoyed the atmosphere, they were singing, dancing, joining in and just having a good time.”
Alexander Booth, who was on the trip with Nigel and father Chris Booth, spent his 20th birthday in a cell after being arrested near the Vieux Port area of Marseille after trouble flared.
Nigel Booth said his nephew was guilty of giving the police “a few verbals” after being pepper sprayed, but is adamant he did not throw anything towards police.
He said: “We thought at the worst he’ll be deported ... then I heard he had got two months in prison.
“It was devastating.”
During his court case in Marseille earlier this month, Alexander Booth said: “I would like to say sorry to the police and to the people and city of Marseille.
“I was in the wrong place at the wrong time.”
Two other Yorkshire fans, Ian Hepworth and Paul Jackson, were jailed along with Booth.
Hepworth, 41, a psychiatric nurse from Sheffield, was given a three month sentence and ban.
Jackson, 21, from Halifax, was jailed for a month and banned for two years for throwing bottles at police and supporters.